Adaptive on-off control for radio receiver

• US 5,309,153 A
• Filed: 03/13/1991
• Issued: 05/03/1994
• Est. Priority Date: 11/27/1985
• Status: Expired due to Term

• Current Assignee: Protocol-ip.com, LLC, Seiko Instruments Incorporated (Seiko Group)
• Original Assignee: Seiko Corporation (Seiko Group), Seiko Epson Corporation (Seiko Group)
• Inventors: Park, Daniel J., Gaskill, Garold B.
• Primary Examiner(s): Yusko, Donald J.
• Assistant Examiner(s): ZIMMERMAN, BRIAN A
• Application Number:
  US07/668,389
• Time in Patent Office: 1,147 Days
• Field of Search: 340/825.44, 340/825.47, 455/38.2, 455/38.3, 455/343, 370/100.1, 370/105.4, 370/106, 370/105.5
• US Class Current: 340/7.33
• CPC Class Codes: G04G 21/04 using radio waves radio-controlled time-pieces G04R
• CPC Class Codes: G04R 20/14 the radio signal being a telecommunication standard signal, e.g. GSM
• CPC Class Codes: G04R 20/20 the radio signal being an AM/FM standard signal, e.g. RDS
• CPC Class Codes: G04R 60/04 Antennas attached to or integrated in watch bracelets
• CPC Class Codes: G08B 3/1016 using wireless transmission calling systems using transmission by inductive loop H04B5/00
• CPC Class Codes: G08B 5/222 Personal calling arrangements or devices, i.e. paging systems selective calling systems and call receivers H04W84/00, H04W68/00
• CPC Class Codes: G08B 5/223 using wireless transmission
• CPC Class Codes: H04L 1/18 Automatic repetition systems, e.g. Van Duuren systems
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 88/022 Selective call receivers
• CPC Class Codes: H04W 88/026 using digital address codes
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A paging system using synchronized transmission protocol and pagers active during monitor intervals to receive data transmitted during corresponding message intervals is provided with adaptive on-off radio receiver control for reducing monitor interval duration to conserve battery power. The adaptive on-off control is a function of recent timing errors and thereby accounts for environmental conditions.

Claims

1. A radio paging receiver for a paging system which transmits signals from a transmitter to said paging receiver according to a time slot protocol, said radio paging receiver including,

periodically active radio circuit means which is periodically active for short periods of time to receive signals from said transmitter,

an internal timing reference in said radio circuit for generating an internal timing reference signal,

means for generating first timing signals from said internal timing reference signals,

means responsive to said first timing signals for controlling the interval during which said radio circuit means is active and the interval during which said radio circuit means is inactive,

means for deriving a second timing signal each time said radio circuit means is active, said second timing signal being derived from said signal transmitted by said transmitter,

means for modifying the relationship between said internal timing reference and said first timing signals if the sum of sequentially accruing active and inactive periods of said radio circuit means do not equal the time interval between sequential ones of said second timing signals,

whereby the activation of said radio circuit means in said paging receiver is synchronized with the transmission from said transmitter.

2. A radio receiver for receiving signals from a radio transmitter, said transmitter transmitting signals in accordance with a time slot protocol, said receiver comprising

radio receiver means which are periodically active for short periods to receive signals from said transmitter,

an internal timing reference in said radio receiver means which generates first timing signals which control the active and inactive periods of said radio receiver,

means for deriving a first timing measurement from the signals received from said transmitter,

means for deriving a second timing measurement from said internal timing reference,

means for changing the relationship between said internal timing reference and said first timing signals if said first and second timing measurements are not equal,

means for activating said radio receiver in response to said first timing signals,

whereby the activation of said radio receiver is synchronized with said time slots in said time slot protocol of said transmitter.

3. In a communication system where a transmitter and a receiver are synchronized and wherein information is transmitted from the transmitter to the receiver according to a time slot protocol,

a method for compensating for timing inaccuracy in a timing circuit relative to events of a time frame taken as being accurate, said time frame being related to the time slots in said time slot protocol, the method comprising the steps:

calculating a first expected offset between a first event of said time frame and a second event of said time frame;

using said timing circuit to initiate a first communication activity between said transmitter and said receiver based on the expected offset;

calculating a timing error based on an offset between said second event and initiation of said communication activity;

calculating a second expected offset between said second event of said time frame and a third event of said time frame including compensation based on said timing error; and

using said timing circuit to initiate a second communication activity from said transmitter to said receiver based on said second expected offset,

whereby the amount of timing error associated with said second communication is reduced.

4. A method according to claim 3 wherein said communication system comprises a radio communication system wherein the transmitter transmits message packets to said receiver during predetermined time slots associated with said receiver and said receiver activates during monitor intervals to receive said message packets.

5. A method according to claim 3 in a synchronized radio paging system wherein the timing circuitry is timing circuitry in a radio pager,

a broadcast facility broadcasts message packets to radio pager during predetermined time slots associated with the pager,

said radio pager deactivates a portion of its circuitry to reduce power consumption between said first event and the second events.